1 /* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5 #include <cstring>
6 #include <dlfcn.h>
7 #include <fcntl.h>
8 #include <linux/ashmem.h>
9 #include <stdio.h>
10 #include <sys/stat.h>
11 #include <sys/types.h>
12 #include <sys/ioctl.h>
13 #include <unistd.h>
14
15 #include "Ashmem.h"
16
17 namespace mozilla {
18 namespace android {
19
libhandle()20 static void* libhandle() {
21 static void* handle = dlopen("libandroid.so", RTLD_LAZY | RTLD_LOCAL);
22 return handle;
23 }
24
ashmem_create(const char * name,size_t size)25 int ashmem_create(const char* name, size_t size) {
26 static auto fCreate =
27 (int (*)(const char*, size_t))dlsym(libhandle(), "ASharedMemory_create");
28
29 if (fCreate) {
30 return fCreate(name, size);
31 }
32
33 int fd = open("/" ASHMEM_NAME_DEF, O_RDWR, 0600);
34 if (fd < 0) {
35 return fd;
36 }
37
38 if (name) {
39 char str[ASHMEM_NAME_LEN];
40 strlcpy(str, name, sizeof(str));
41 ioctl(fd, ASHMEM_SET_NAME, str);
42 }
43
44 if (ioctl(fd, ASHMEM_SET_SIZE, size) != 0) {
45 close(fd);
46 return -1;
47 }
48
49 return fd;
50 }
51
ashmem_getSize(int fd)52 size_t ashmem_getSize(int fd) {
53 static auto fGetSize =
54 (size_t(*)(int))dlsym(libhandle(), "ASharedMemory_getSize");
55 if (fGetSize) {
56 return fGetSize(fd);
57 }
58
59 return (size_t)ioctl(fd, ASHMEM_GET_SIZE, nullptr);
60 }
61
ashmem_setProt(int fd,int prot)62 int ashmem_setProt(int fd, int prot) {
63 static auto fSetProt =
64 (int (*)(int, int))dlsym(libhandle(), "ASharedMemory_setProt");
65 if (fSetProt) {
66 return fSetProt(fd, prot);
67 }
68
69 return ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
70 }
71
72 } // namespace android
73 } // namespace mozilla
74